1. Field of the Invention
The present invention is for a railroad gate release mechanism, and in particular, is for a railroad gate release mechanism which allows for maintaining of structural integrity of a railroad grade crossing arm during and subsequent to being struck by an automotive vehicle. Although a railroad gate release mechanism is described, the release mechanism can be incorporated for other uses such as, but not limited to, parking lot gates, restricted access gates, road closure gates, toll gates, and the like.
2. Description of the Prior Art
Railroad crossing grades are protected by railroad grade crossing arms which are stored substantially in a vertical position and which are actuated by railroad gate actuators which reorient the crossing arms to a horizontal position across a railroad grade crossing to warn operators of vehicles of oncoming train traffic and to physically place a barrier in the form of a crossing arm at both sides of the railroad grade crossing to prevent passage of a vehicle into the railroad grade crossing. Motorists unaware of the movement of a crossing arm may impinge the crossing arm to the extent that physical damage occurs where the crossing arm is broken and parted from the railroad gate actuator. Such an occurrence can compromise the safety of the railroad grade crossing in that other motorists will not be warned of impending danger due to the destruction of the crossing arm. Such occurrences compromise safety, as well as add a financial maintenance burden. Maintenance of prior art railroad grade crossing arms sometimes required that the railroad grade crossing arms be deployed across the railroad crossing grade, thus providing a nuisance and hinderance to the smooth flow of vehicle traffic across the railroad crossing grade.
The general purpose of the present invention is to provide a railroad gate release mechanism.
According to one embodiment of the present invention, there is provided a railroad gate release mechanism for attachment between a railroad gate actuator and a crossing arm including opposing channel-shaped brackets which attach to a railroad gate actuator and which also serve as mounting structure for other components of the railroad gate release mechanism. A pivotable arm assembly, to which a crossing arm is attached, pivotally mounts between bearing plates located on the inwardly facing surfaces of the opposing channel-shaped brackets. The pivotable arm assembly is influenced by a detent and plunger arrangement which maintains a perpendicular relationship of the pivotable arm assembly and the attached crossing arm with respect to the railroad gate actuator until acted upon by outside forces, such as a vehicle impinging the crossing arm. Such impingement causes the railroad gate release mechanism, with the attached crossing arm, to pivotally overcome the influence of the detent and plunger arrangement and to swing substantially horizontally out of the way of the impinging vehicle without functional damage to the crossing arm. Such pivotal breaking away substantially reduces the possibility of breakage of the crossing arm, as little bending moment is actually applied to the crossing arm itself due to the substantially unrestricted movement allowed by the railroad gate release mechanism. Subsequent to such impingement and when the vehicle has ceased to contact the crossing arm, spring assemblies function to return the pivotable arm assembly of the railroad gate release mechanism, with the attached crossing arm, to the detented position to continue to offer gated protection at the crossing grade. A shock absorber allows for rapid rate pivoting of the pivotable arm assembly in one direction during impingement and allows for a slower rate return of the pivotable arm assembly in the return direction subsequent to impingement. A centering spring assists in returning of the pivotable arm assembly to the detented position.
An alternative embodiment of the present invention involves a railroad gate release mechanism which allows maintenance of the a railroad gate release mechanism without requiring sustained horizontal positioning of the crossing arm across the railroad crossing grade. Such a device includes an additional pivotal arrangement and a readily detachable bracket for pivotal release of the crossing arm from the pivotable arm assembly to facilitate maintenance functions.
One significant aspect and feature of the present invention is a railroad gate release mechanism which secures between the mount arms of a railroad gate actuator and a crossing arm.
Another significant aspect and feature of the present invention is a railroad gate release mechanism which when impinged releasably allows breakaway pivoting in two directions of a crossing arm from a normal and detented position to prevent damage to the crossing arm.
Another significant aspect and feature of the present invention is a railroad gate release mechanism which allows return pivoting of a crossing arm to a normal and detented position subsequent to breakaway pivoting caused by impingement.
Still another significant aspect and feature of the present invention is a railroad gate release mechanism which offers grade crossing protection subsequent to crossing arm impingement.
Yet another significant aspect and feature of the present invention is the use of cables attached to a pivotable arm assembly which connect to springs in spring assemblies which are compressed during impingement with the front side of a crossing arm to subsequently power the return of the pivotable arm assembly and attached crossing arm to an original and detented position.
A further significant aspect and feature of the present invention is the use of a shock absorber which allows rapid deployment and release of a pivotable arm assembly and attached crossing arm during impingement and which allows return of the pivotable arm assembly and attached crossing arm at a slower rate subsequent to impingement, whereby the slower return rate reduces return overshoot of the pivotable arm assembly and the crossing arm.
A still further significant aspect and feature of the present invention is the use of a centering spring assembly which urges the pivotable arm assembly into a normal and detented position when the crossing arm is impinged from the rear side.
Yet another significant aspect and feature of the present invention is a pivotable arm assembly which allows maintenance of a crossing arm without requiring sustained horizontal positioning of the crossing arm across the railroad crossing grade.
Having thus described an embodiment of the present invention and set forth significant aspects and features thereof, it is the principal object of the present invention to provide a railroad gate release mechanism.